Airway device with tongue-engaging member

ABSTRACT

An oral device for improving airway patency comprises a base adapted to be held between a patient&#39;s upper and lower teeth and a tongue-engaging member. The tongue-engaging member engages the tongue and displaces the tongue anteriorly when the base is held between the patient&#39;s teeth. A vacuum is applied through the base and the tongue-engaging member in order to draw the soft palate against a posterior region of the tongue in order to stabilize the soft palate and open or clear the patient&#39;s airway.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.12/840,076 (Attorney Docket No. 41506-704.201), filed on Jul. 20, 2010,and is also a continuation-in-part of U.S. application Ser. No.13/365,791 (Attorney Docket No. 41506-703.401), filed on Feb. 3, 2012,which was a divisional of U.S. application Ser. No. 12/269,683 (AttorneyDocket No. 41506-703.201), filed on Nov. 12, 2008 now U.S. Pat. No.8,122,889, which claimed the benefit of Provisional Application No.60/987,707 (Attorney Docket No. 41506-703.101), filed on Nov. 13, 2007,the full disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical devices and methods.In particular, the present invention relates to an oral device that maybe held in the mouth of a patient to reduce the incidence of obstructivesleep apnea or snoring.

Obstructive sleep apnea (OSA) is a serious medical condition resultingfrom a temporary airway blockage which occurs as a patient sleeps. Theairway blockage usually occurs between the soft palate and/or the backof the tongue and the pharynx. As the patient breathes, the reduced areain the upper airway can cause snoring, and more seriously, OSA.

Sleep disruption caused by OSA can result in severe daytime sleepiness,chronic fatigue, headaches, depression, accidents, injuries, and ofparticular concern, OSA can reduce the amount of oxygen entering thelungs causing hypoxia. Hypoxia, in turn, can lead to pulmonaryhypertension, heart disease, and stroke.

Numerous invasive and less invasive treatments have been proposed forOSA. Of particular interest to the present invention, “continuouspositive airway pressure” (CPAP) delivers a continuous stream ofpressurized air directly to the person's upper airway. The positivepressure maintains patency of the airway and inhibits the collapseassociated with OSA. Although generally effective, CPAP suffers from anumber of drawbacks that have led to a high level of non-compliance. Thepatient must wear a bulky facial mask which can be uncomfortable, andthe system generates noise that can make falling asleep difficult. CPAPis also difficult to use because the mask requires careful fitting toavoid air leaks and facial discomfort and because the mask can easily bedislodged during sleep. Moreover, a number of unpleasant side effects,such as sore throats, dry throat and eyes, headaches, and skin rashesfrom the mask frequently occur. These problems have resulted in a highlevel of non-compliance with CPAP therapy.

As an improvement over CPAP, it has been proposed to apply a negativepressure to the forward end of the patient's mouth, typically at or justbehind the lips, to pull the tongue forward in order to lift the rearportion of the tongue away from the back of the airway. See, forexample, U.S. Patent Publication Nos. 2007/0277818, 2005/0166928 and2005/0166929. While promising in theory, in practice it is verydifficult to apply a vacuum in the region of the tip of the tongue toraise the base of the tongue and clear the patient's airway,particularly when the patient is lying on his or her back and gravity ispulling the tongue posteriorly. The tongue is a relatively large andcompliant organ with significant mass, and applying a vacuum over arelatively small surface area at the tip will often not be effective inraising the back of the tongue against gravity. The moist and complianttissues in the mouth are somewhat self-sealing, and this effect tends toinhibit the propagation of negative pressure, thereby confining thenegative pressures to a relatively small area near the point ofapplication. Thus, simply applying a vacuum at a location near theanterior tip of the tongue tends to draw the tongue up against the hardpalate posterior to this location, creating a seal that restricts thepropagation of vacuum through this region of contact toward the back ofthe oral cavity, where direct vacuum is usually required for maximumeffectiveness.

As another improvement over CPAP, it has been proposed to place variousdevices in direct contact with the posterior tissues of the mouth suchas the soft palate and posterior portions of the tongue. A majordisadvantage of these approaches is that contact with certain tissuesnear the posterior area of the tongue may elicit the gag reflex and inany case the presence of such devices so far back in the mouth can beuncomfortable.

For these reasons, it would be desirable to provide alternative andimproved methods and apparatus for treating obstructive sleep apnea andsnoring. The methods and devices should be non-invasive and require nosurgery or permanently implanted components. In addition, the methodsand devices should be minimally intrusive with components that arecomfortable and quiet so that disruption of the patient's sleep isminimized. Moreover, the methods and devices should avoid contacting theportions of the oral cavity that trigger the gag reflex. The methods andsystems should also be simple to implement and be effective tosignificantly improve patency of a patient's airway during sleep. Atleast some of these objectives will be met by the inventions describedhereinafter.

2. Description of the Background Art

Oral and external devices for treating sleep apnea and snoring aredescribed in U.S. Patent Publication Nos. US2005/166929; US2005/166928;US2008/0188947; US2007/0277818; US2008/0216843; and US2008/0210244; andin U.S. Pat. Nos. 7,182,082; 7,073,506; 7,073,505; 6,955,172; 6,877,513;6,494,209; 5,957,133; 5,465,734; 4,676,240; 4,304,227; 4,169,473; and3,132,647; and in Cartwright and Samelson “The effects of a non-surgicaltreatment for obstructive sleep apnea: the tongue retaining device;”Journal of the American Medical Association 248 (1982). The presentinvention provides improvements over the devices and methods describedin commonly-owned published patent applications 2009/0120446;2009/0120447; and 2009/123886, the full disclosures of which areincorporated herein by reference.

SUMMARY OF THE INVENTION

The present invention provides devices and methods for improving airwaypatency in patients by engaging a member against the tongue to move thetongue in an anterior direction and allow a vacuum to be drawn betweenthe tongue-engaging member and the soft palate to draw the soft palateaway from the pharynx and toward a posterior region of the tongue. Bythus drawing the soft palate away from the pharynx, the patient's airwayremains clear and the risk of obstructive sleep apnea (OSA) is greatlyreduced. The tongue-engaging member is attached to a base and hasposterior and anterior surfaces. The anterior surface is inclinedforwardly relative to a plane of the base when the base is positionedbetween the upper and lower teeth and engages a medial region of thetongue to effect anterior tongue displacement. The anterior andposterior surfaces of the tongue-engaging member are usually paralleland inclined at an angle in the range from 45-60° relative to a planewhich is defined between the patient's teeth, with the tongue-engagingmember extending upwardly from the plane by a distance which issignificantly greater than it extends downwardly. This particulargeometry, which is described in greater detail hereinbelow, has beenfound to provide for particularly effective sealing between the softpalate and the posterior region of the tongue with greater patientcomfort and reduced risk of inducing the gag reflex.

Oral devices constructed in accordance with the principles of thepresent invention will include a base, a vacuum conduit, a lip seal, anda tongue-engaging member. The base is adapted to be held between apatient's upper and lower teeth, and the lip seal is coupled to the baseand passes the vacuum conduit into the oral cavity. The tongue-engagingmember is also coupled with the base and includes an integral plenumwhich is connected to the vacuum conduit. The tongue-engaging memberincludes anterior and posterior surfaces, where at the least theanterior surface is inclined forwardly relative to a plane of the basewhen the base is positioned between the upper and lower teeth anddisposed to engage a medial region of the tongue when the base ispositioned between the patient's teeth. The tongue-engaging member alsoincludes a plurality of ports distributed over its posterior surface.The ports are open to the plenum and permit a vacuum drawn through thevacuum conduit to be applied to the region between the patient's tongueand the soft palate.

In the exemplary embodiments, the anterior and posterior surfaces of thetongue-engaging member are inclined forwardly (i.e. with the upper enddisplaced in the anterior direction) at an angle in the range from 45°to 60° relative to a plane of the base when the device is positionedbetween the upper and lower teeth. Usually, the anterior surface of themember is generally parallel to the posterior surface, and both surfaceswill fall within the range of angles set forth above.

The upper edge of the tongue-engaging member will extend at least 5 mmabove the plane of the base and from 0 mm to 20 mm in an anteriordirection from the patient's molars when the base is positioned betweenthe upper and lower teeth. The tongue-engaging member will have a loweredge which extends up to 8 mm above or below the plane of the base,typically from 0 mm to 5 mm below the plane, and from 0 mm to 5 mm in aposterior direction from the patient's second molars when the base ispositioned between the upper and lower teeth. As the tongue-engagingmember is typically disk-shaped, more typically having a generally ovalperiphery, and the body of the base is planar with rounded edges, themember will be able to conform to the patient's natural anatomy byaligning into space between the soft palate and the medial region of thetongue, allowing the area of the member to be maximized while stillminimizing the discomfort and risk of gagging.

In the exemplary embodiments, the tongue-engaging member will have ananterior surface which engages the tongue with an area in the range from300 mm² to 1000 mm², typically from 550 mm² to 750 mm². Usually,although not necessarily, the posterior surface will have an area whichis generally in the same range from 450 mm² to 1000 mm², usually from600 mm² to 850 mm². In certain preferred embodiments, the upper edge ofthe tongue-engaging member will be curved or otherwise deflected in ananterior direction in order to increase or enhance pushing of the tongueanteriorly when the base is positioned between the upper and lowerteeth.

The tongue-engaging member can be positioned at the target regionbetween the medial tongue and the soft palate in a variety of ways. Mostcommonly, the tongue-engaging member will be supported on a base whichcomprises a U-shaped bite plate configured to be positioned between thefull dentition. The tongue-engaging member can then be positionedbetween the posterior ends of the legs of the bite plate. Alternatively,the base may comprise left and right molar bite plates which are notjoined or held together in other than a U-shaped configuration, wherethe tongue-engaging member is suspended between the separate biteplates.

In a still further embodiment, the tongue-engaging member may be coupledto and suspended from an axial bridge which joins the tongue-engagingmember to a base which is typically held between the patient's frontteeth. In still further embodiments, the tongue-engaging member maycomprise two or more separate enclosures providing separate plenums,such as a right enclosure and a left enclosure which may be separatelyjoined to left and right portions of the base.

Methods according to the present invention stabilize a soft palate in apatient's oral cavity, typically for the purpose of treating sleep apneaor other breathing disorders. The methods may utilize the apparatusdescribed above or, alternatively, may employ different devices andsystems capable of achieving the same soft palate stabilization. Ananterior surface of a member is engaged against a medial region of thetongue where the anterior surface is inclined forwardly relative to aplane of the base when the base is positioned between the upper andlower teeth and displaces the medial region in an anterior directionrelative to the soft palate to provide a clearance between the softpalate and the tongue, typically the medial region of the tongue. Avacuum is applied within the clearance through a posterior surface ofthe member, where the vacuum draws together the soft palate in aposterior region of the tongue to move a posterior surface of the softpalate away from the pharynx.

In the specific embodiments, the anterior surface is inclined at anangle in the range from 45° to 60° relative to a bite plane between thepatient's upper and lower teeth. The member will have an upper edge anda lower edge, where the lower edge extends up to 8 mm above or below thebite plane and from 0 mm to 5 mm in a posterior direction from thepatient's second molars. The upper edge will extend at least 5 mm abovethe bite plane, and from 0 mm to 20 mm in an anterior direction from thepatient's second molars. The anterior surface of the member engages thetongue over an area in the range from 300 mm² to 1000 mm², preferablyfrom 550 mm² to 750 mm², and the vacuum may draw the soft palate againstthe posterior surface of the member or the soft palate may remainspaced-apart from the posterior surface while the vacuum is beingapplied. In a particularly preferred configuration, the upper edge ofthe member is deflected in an anterior direction to increase theanterior displacement of the tongue while the remaining body of themember remains inclined forwardly relative to a plane of the base whenthe base is positioned between the upper and lower teeth, preferablywithin the angle of inclination defined above.

The inclination of the cross member as described above allows for theoral device to position the tongue appropriately for vacuumstabilization of the soft palate and tongue, while smoothing thetransition of the tongue from a point of initial contact with the roofof the mouth. Such smoothing makes the device more comfortable andpositions the tongue more repeatably, improving both patient complianceand device effectiveness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the relevant anatomy of the nasal and oral cavities.

FIGS. 2A and 2B illustrate a first embodiment of an oral deviceconstructed in accordance with the principles of the present invention,with FIG. 2A shown in full line perspective view and FIG. 2B shown withportions broken away.

FIG. 3 is a side view of the oral device of FIGS. 2A and 3B.

FIG. 4 is a side view of a second embodiment of an oral deviceconstructed in accordance with the principles of the present invention.

FIG. 5 is a perspective view of a third embodiment of an oral deviceconstructed in accordance with the principles of the present invention.

FIG. 6 is a perspective view of a fourth embodiment of an oral deviceconstructed in accordance with the principles of the present invention.

FIGS. 7 and 8 are schematic illustrations of the placement of the oraldevice of FIG. 4 in an oral cavity with the soft palate engaging aposterior surface of the device in FIG. 7 and the soft palatespaced-apart from the oral device in FIG. 8.

FIG. 9 is a schematic illustration of a control system or console foruse in aspirating a negative pressure in the oral devices of the presentinvention.

FIGS. 10A-10B are oblique and side cross-sectional views, respectivelyof an oral device according to the invention in still another embodimentthereof, in which the lip seal is removed for clarity.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the anatomy of the oral and nasal cavities relevantto obstructive sleep apnea (OSA) and the placement of the devices of thepresent invention will be described. The upper teeth UT of the patientare anchored in the hard palate HP, and the lower teeth LT are anchoredin the lower jaw or mandible LJ. The soft palate SP extends in arearward or posterior and inferior direction from the hard palate, andtogether the hard palate and soft palate divide the nasal airway NA fromthe oral cavity OC. The lower extent of the oral cavity is largelydefined by the upper surface of the tongue T in this view, and it willbe appreciated that both the soft palate SP and the tongue are mobilestructures capable of movement between the positions shown in full lineand broken line in FIG. 1. A nasal airway NA extends inferiorly into thepharynx P which defines the airway generally behind the soft palate SPand the tongue T. The regions on the tongue and soft palate shown with aheavy dashed line are the areas responsible for the gag reflex GR.

Obstructive sleep apnea occurs when either the soft palate, the tongueor both move in a posterior direction so that they contact the rear orposterior surface of the pharynx P. The posterior motion of the softpalate and/or tongue may also reduce the size of the airway withoutcontacting the pharynx P causing a partial blockage. The temporaryblockage of the airway behind the soft palate and tongue will cause thedisrupted breathing pattern characteristic of OSA and usually associatedwith snoring.

As used herein, “superior” refers to the direction toward the top of theoral cavity (or top of the head), “inferior” refers to the directionopposite the superior direction, “anterior” refers to the directiontoward the front of the oral cavity or lips, and “posterior” refers tothe direction toward the back of the oral cavity and airway, oppositethe anterior direction. The terms “patency” and “airway” refer to theopening or clearing of the airway leading from the nasal cavity into thetrachea located generally behind the soft palate and the rear of thetongue. To improve airway patency, the airway may be wholly or partiallyobstructed intermittently or temporarily for some time period over anormal sleep cycle, however, the airway will be open or partially openmore than it would in the patient's untreated condition. The “upperportion of the soft palate” refers to the superior portion of the softpalate extending inferiorly from the end which connects to the hardpalate to a point about ⅓-½ way toward the free inferior tip of the softpalate. The phrase “medial region” or “medial surface” of the tonguerefers to a superior surface of the tongue which is spaced substantiallyposteriorly from the anterior tip of the patient's tongue andimmediately anterior or forward of the region which initiates the gagreflex. While it may vary from patient to patient, the medial regionwill generally be the middle one third of the upper surface of thetongue which extends between the anterior tip of the tongue and theposterior end of the tongue (the posterior end being the location on thetongue that is furthest posterior in the oral cavity); i.e., the medialsurface will usually include an area of the tongue that is at leastabout ⅓ of the way, more preferably at least about ½ of the way, fromthe anterior tip of the tongue to the posterior end of the tongue.Preferably, the medial region will include an area on the tongueposterior to the midpoint between the anterior and posterior ends of thehard palate. The phrase “clear region” refers to the space or volumeabove and/or posterior of the tongue which will be cleared by themethods and devices of the present invention. The clearing will usuallybe achieved by engaging a surface which is inclined forwardly relativeto a plane of the base when the base is positioned between the upper andlower teeth and against the superior surface of the tongue, typicallyusing a member or element which engages the tongue and which is anchoredwithin the oral cavity so as to simultaneously advance the tongue in ananterior direction and depress the tongue in an inferior direction toopen or maintain the clear region and allow the negative pressure todraw the soft palate against the tongue. The term “vacuum” and thephrase “negative pressure” each refers to a total or partial vacuumwhich is maintained in the clear region, typically by controlledaspiration, where the pressure is maintained primarily in the range from5 cm H₂O to 150 cm H₂O below the local atmospheric pressure. The“occlusal plane” is the plane in which the upper and lower teeth meetwhen the patient bites the upper and lower teeth together.

Referring now to FIGS. 2A and 2B, a first exemplary oral device 10constructed in accordance with the principles of the present inventioncomprises a U-shaped base or anchor structure 12 having a lip seal 14 atits forward or anterior end. A tongue-engaging member 16 is held betweenthe posterior ends of right and left legs of the U-shaped base 12, and avacuum tube 18 passes into the device and is open within a plenum 20 inorder to draw a vacuum within the device. In particular, the plenum 20is open to an interior 22 of the tongue-engaging member 16 so that thevacuum may be drawn via a conduit 24 provided through one of theconnecting wings 26 which couple the tongue-engaging member 16 to thebase 12. A plurality of ports 28 are formed over a posterior surface 30of the tongue-engaging member 16 so that a vacuum may be applied withinthe oral cavity when the device 10 is held with the base anchor 12positioned between the patient's upper and lower teeth. Typically, thepatient's teeth will be placed within upper and lower channels 13 (withonly the upper channel being shown in FIGS. 2A and 2B) which are formedin the upper or superior and lower or inferior surface of the base 12.

As best shown in FIG. 3, the tongue-engaging member 16 has both theposterior surface 30 and an anterior surface 32, where the anteriorsurface will engage the tongue when the base 12 is held between thepatient's teeth. The anterior surface of the tongue-engaging member willtypically be flat or slightly curved in order to engage a medial regionof the tongue over a relatively large surface area, typically in therange from 300 mm² to 1000 mm², usually from 550 mm² to 750 mm². Ofparticular interest to the present invention, the tongue-engaging member16 will be inclined with an upper end or lip 34 displaced in an anteriordirection (toward the lip seal 14) and a lower or inferior lip or edge36 being displaced in a posterior direction. The tongue-engaging member16 will typically have a center line 38 (shown in broken line) which isinclined at an angle α in the range from 30° to 70°, usually from 45° to60°, relative to a plane 40 (shown in broken line) of the base, which ispositioned between the patient's teeth during use of the device. Therelatively large area of the anterior surface 32 of the device 10combined with the angle of inclination, which is generally inclinedforwardly relative to a plane of the base when the base is positionedbetween the upper and lower teeth, combines for particularly effectiveanterior displacement of the patient's tongue while creating a clearregion above the medial region of the tongue in order to apply a vacuumto close the soft palate against the posterior region of the tongue, asdescribed in more detail below.

Oral device 50 (FIG. 4) represents a second embodiment of the presentinvention and includes a U-shaped base or anchor 52 having an enlargedlip seal 54 at its anterior end. A tongue-engaging member 56 is carriedat the posterior end of the base 52 and has a body which is generallyaligned along a plane 58 (shown in broken line) which is disposed at thesame angle α relative to the plane of the base 60 (broken line) as withthe first device illustrated in FIG. 3. A principal difference of theoral device 50 is that an upper edge 62 of the tongue-engaging member 56is inclined in a forward or anterior direction, generally with a curvedanterior surface 64. The remaining aspects of the oral device 50 aregenerally the same as described above with respect to the first oraldevice 10. Use of the oral device 50 is described in more detail inconnection with FIGS. 7 and 8.

Referring now to FIG. 5, an oral device 70 comprises a U-shaped base oranchor 72 having a lip seal 74 at its forward or anterior end. A vacuumtube or line 76 is connected to the device in order to apply a vacuumwithin an interior of the base 72. A tongue-engaging member 78 comprisesa right half 80 and a left half 82 (where right and left are viewed fromthe anterior end of the device which includes the lip seal 74). Each ofthe right and left halves 80 and 82 are connected to a vacuum plenum(not illustrated) formed through both sides of the interior of base oranchor 72 so that the vacuum applied through vacuum tube 76 is carriedthrough to the ports 84 and 86 formed on the two halves, respectively.The angle of inclination of the two halves will typically be identical,but it could vary by a small amount without departing from theeffectiveness of the present invention. The inclination angle(s) andtotal contact area of the anterior surfaces of the halves 80 and 82 arealso within the ranges set forth above, so that the effectiveness of thedevice is generally the same as described for the previous devices.

Referring now to FIG. 6, an oral device 90 represents a fourthembodiment of the present invention and comprises an interior bite plateand lip seal 92 connected to a single axial bridge 94 which carries atongue-engaging member 96 at its posterior end. The tongue-engagingmember 96 has generally the same dimensions and is inclined at the sameangle relative to a bite plane as described with the prior embodiments.A vacuum is applied through a vacuum tube 98 which is connected via aplenum (not shown) within the single axial member 94 which opens to theinterior of the tongue-engaging member 96. The vacuum is applied througha plurality of ports 100. The device 90 is less bulky than the priorembodiments.

Referring to FIGS. 7 and 8, use of the device 50 for positioningtongue-engaging member 56 against a tongue within an oral cavity will bedescribed. In a first instance, as shown in FIG. 7, anterior surface 57of the tongue-engaging member 56 engages the medial region of the tongueT to push or displace the tongue in an anterior direction. By applying avacuum through ports on the posterior surface 59, the soft palate SP isalso drawn in an anterior direction so that a posterior portion PP ofthe palate seals against a posterior region PR of the tongue, asillustrated. The region of the soft palate above the posterior portionis also drawn against the posterior surface 59 of the tongue-engagingmember 56, to further stabilize the soft palate to treat the breathingdisorder.

The portion of the soft palate SP above the posterior portion PP neednot be engaged against the posterior surface 59 of the tongue-engagingmember 56. As shown in FIG. 8, an open space OS may remain between theposterior surface 59 and the soft palate SP while the posterior portionPP of the soft palate remains engaged with the posterior region PR ofthe tongue. The soft palate remains sufficiently stabilized in order totreat the breathing disorders within the methods of the presentinvention.

A vacuum can be applied to any of these devices via a tabletop controlunit 200 having a plurality of tubes 230 connected to the device andwhich comprises a number of internal components, as best illustrated inFIG. 9. The tabletop control unit will usually include a user interface204. In order to generate the negative pressure used by the oral devicestypically from 25 cmH₂O to 75 cmH₂O, described above and to reduce theaccumulation of fluid within the mouth, one or more pumps 220, sensors222 for flow, pressure, or the like and traps 224 will usually beprovided. The traps 224 remove saliva and other substances from thetubing to prevent them from entering the pumps 220. The sensors 222 maybe used to determine if the device is operating and being appliedproperly. For example an air leak would generate higher than normal flowand the user could be alerted that there is a problem. Optionally valve232 may be provided for briefly allowing air to enter the device or oralcavity in order to facilitate aspiration of fluids that have collectedin the oral cavity or device. Optionally fluid source 214 and pump 206for providing moisture and a heater/cooler 216 for heating or coolingthe fluid, may be provided. Electronics and power control module 208will provide for the desired control functions of the unit. Optionally afeedback loop may be configured to monitor the pressure in the oralcavity for example as described above using one of tubes 230 connectedto a pressure sensor 212 and to adjust the power of the one or morevacuum pumps 220 in order to maintain the desired level of negativepressure in the oral cavity. Varying distributions of saliva in thetubing that connects the control unit 200 to the oral devices describedabove will create a pressure differential and such a feedback loop couldcontinually compensate for this varying differential. Optionally, a port210 may be provided for external connection of the control unit to acomputer or data distribution network. Each of these components may beconnected to the oral device through appropriate tubes, wires or otherconnectors 230.

FIGS. 10A-B illustrate a further embodiment of an oral device accordingto the invention. In this embodiment, like other embodiments elsewheredescribed, oral device 400 comprises a tongue constraint 402 and a bitestructure 404. Tongue constraint 402 comprises a dome-shape plate 403with a plurality of inferior vacuum ports 408 extending through plate403 in a central region thereof. An anterior vacuum tube 406 is fixed tothe superior surface of plate 403 and has a plurality of side holes 405through which vacuum may be conveyed.

Different from previously describe embodiments, a landing pad 410 ispivotally coupled to tongue constraint 402 by a transverse pin 412, sothat landing pad 410 is rotationally movable relative to plate 403.Landing pad 410 has a hollow interior chamber 414 enclosed by aposterior wall 416 and an anterior wall 418. A plurality of posteriorports 420 are disposed in posterior wall 416 in communication withchamber 414. Posterior ports 420 are configured to face the soft palateand away from the tongue, preferably being disposed plane which is at anangle beta of at least about 45° more preferably about 60°-180° and mostpreferably about 90° 180° in the superior direction relative to theocclusal plane. Notably, the angle of posterior ports 420 relative tothe occlusal plane may be varied by pivoting landing pad 410 relative toplate 403.

A posterior vacuum tube 422 is connected to anterior wall 418 incommunication with chamber 414. Posterior vacuum tube 422 extendsanteriorly along the inferior side of plate 403, which optionally mayinclude eyelets 424 through which posterior vacuum tube is slidablypositioned to keep it close to plate 403. Posterior vacuum tube 422extends slidably through bite structure 404 and a clamp 426 fixed to theanterior side thereof. Clamp 426 has a cap 428 threaded onto a taperedreceptacle 430 each having a central passage through which posteriorvacuum tube extends. Tapered receptacle 430 may be axially split and/orsufficiently conformable that tapered receptacle 430 is urged radiallyinward to engage posterior vacuum tube 422 as cap 428 is rotationallytightened. Of course, various clamps suitable for clamping posteriorvacuum tube 422 are well known and may be used in place of the exemplaryclamp illustrated. By sliding posterior vacuum tube 422 anteriorly orposteriorly, landing pad 410 is pivoted relative to plate 403. It shouldbe understood that pull wires, rods, or other means could be usedinstead of posterior vacuum tube to pivot landing pad 403.

Advantageously, different negative pressures may be applied throughanterior vacuum tube 406 and posterior vacuum tube 422 so that thesuction applied to the soft palate through posterior ports 420 may becontrolled independently of the suction applied to the tongue throughinferior ports 408. For example, oral device 400 may be used with thesystem illustrated in FIG. 9. When vacuum has been applied throughposterior ports 420 such the soft palate has become engaged againstlanding pad 410, posterior vacuum tube 422 maybe tensioned to pivotlanding pad 410 anteriorly, thereby helping to draw the soft palatefurther away from the patient's airway. Once landing pad 410 is in thedesired position, clamp 426 may be tightened to lock the posteriorvacuum tube 422 and landing pad 410 in place.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the invention which is defined by the appendedclaims.

What is claimed is:
 1. An oral device for temporary placement in apatient's oral cavity, said device comprising: a base adapted to be heldbetween a patient's upper and lower teeth; a vacuum conduit; a lip sealcoupled to the base and passing the vacuum conduit into the oral cavity;and a tongue-engaging member coupled to the base and having an integralplenum connected to the vacuum conduit, wherein the member has (1)anterior and posterior surfaces where the anterior surface is inclinedforwardly relative to a plane of the base when the base is held betweenthe upper and lower teeth and disposed to engage a medial region of thetongue when the base is positioned between the patient's teeth, and (2)at least one port on the posterior surface of the member and open to theplenum.
 2. An oral device as in claim 1, wherein the tongue engagingmember has a plurality of ports distributed over the posterior surfacethereof.
 3. An oral device as in claim 1, wherein the surfaces of themember are inclined forwardly at an angle in the range from 45° to 60°relative to a plane of the base when positioned between the upper andlower teeth.
 4. An oral device as in claim 1, wherein the anteriorsurface of the member is generally parallel to the posterior surface ofthe member.
 5. An oral appliance as in claim 4, wherein the member has alower edge which extends up to at least 8 mm above or below the plane ofthe base and from 0 mm to 5 mm in a posterior direction from thepatient's second molars when the base is positioned between the upperand lower teeth.
 6. An oral appliance as in claim 5, wherein the memberhas an upper edge which extends at least 5 mm above the plane of thebase and from 0 mm to 20 mm in an anterior direction from the patient'ssecond molars when the base is positioned between the upper and lowerteeth.
 7. An oral device as in claim 6, wherein the upper edge isdeflected in an anterior direction to guide the tongue forwardly whenthe base is positioned between the upper and lower teeth.
 8. An oralappliance as in claim 5, wherein the posterior surface of the crossmember has an area in the range from 600 mm² to 850 mm².
 9. An oralappliance as in claim 7, wherein the anterior surface of the crossmember has an area in the range from 550 mm² to 750 mm².
 10. An oralappliance as in claim 1, wherein the base comprises a U-shaped biteplate configured to be positioned between the full dentition.
 11. Anoral device as in claim 1, wherein the base comprises separated left andright molar bite plates configured to be held between at least theopposed upper and lower molars.
 12. An oral device as in claim 1,wherein the base comprises a front bite plate configured to be heldbetween at least the opposed upper and lower front teeth.
 13. An oraldevice as in claim 1, wherein the member consists of a single enclosureenclosing the plenum.
 14. An oral device as in claim 12, furthercomprising left and right connectors which join the single enclosure toleft and right portions of the base.
 15. An oral device as in claim 12,further comprising an axial bridge which joins the single enclosure toan anterior portion of the base.
 16. An oral device as in claim 1,wherein the tongue-engaging member comprises two or more enclosuresenclosing separate plenums.
 17. An oral device as in claim 15, whereinthe tongue-engaging member includes a right enclosure and a leftenclosure with an opening therebetween.
 18. An oral device as in claim16, further comprising left and right connectors which join the left andright enclosures to left and right portions of the base.
 19. A methodfor stabilizing a soft palate in a patient's oral cavity, said methodcomprising: engaging an anterior surface of a member against a medialregion of the tongue, wherein the anterior surface is inclined forwardlyrelative to a plane of the base when the base is held between the upperand lower teeth to displace the medial region of the tongue in ananterior direction relative to the soft palate to provide a clearancetherebetween; and applying a vacuum within the clearance through aposterior surface of the member to draw together the soft palate and aposterior region of the tongue.
 20. A method as in claim 19, wherein theanterior surface is inclined at an angle in the range from 45° to 60°relative to a bite plane between the patient's upper and lower teeth.21. A method as in claim 20, wherein the member has a lower edge whichextends up to 8 mm above or below the bite plane and from 3 mm to 5 mmin a posterior direction from the patient's second molars.
 22. A methodas in claim 21, wherein the member has an upper edge which extends atleast 5 mm above the bite plane and from 0 mm to 20 mm in an anteriordirection from the patient's second molars.
 23. A method as in claim 21,wherein the anterior surface engages the tongue over an area in therange from 550 mm² to 750 mm².
 24. A method as in claim 19, wherein thevacuum draws the soft palate against the posterior surface of themember.
 25. A method as in claim 19, wherein the soft palate remainsspaced-apart from the posterior surface of the member while the vacuumis being applied.
 26. A method as in claim 19, wherein an upper edge ofthe member is deflected in an anterior direction to increase theanterior displacement of the tongue.